The present invention relates to improving the accuracy of automatic weapons such as handguns, and the class of handguns to which the accurizer is adaptable or applicable includes most semi-automatic weapons of variable calibers which incorporate a design in which a slide-barrel recoil assembly is used. In such guns the barrel moves inside the slide. Typically, the initial round is loaded into the firing chamber by manually pulling the slide rearward against the recoil spring or other energy storing mechanism; upon release the slide moves forward to chamber the round and locks the barrel-slide assembly. Subsequent rounds are similarly chambered by the action of compressed gases from a fired round which also recoil the barrel a short distance (relative to slide travel), retract the spent cartridge case, and cause the rearward travel of the slide. The sights used by the operator to aim at an intended target, are a part of or affixed to the slide. The barrel, through which the projectile is fired, is a separate part. Thus, any misalignment of the slide and barrel while in the firing position (up, down, right, or left) will lessen accuracy.